If you are looking for help with this shoulder then I agree with previous posts that practitioners familiar with S. Sahrmann's work or who are kinetic control trained are you best bet. There is I believe a Canadian (?was from Quebec area) who lectures on the Kinetic Control circuit, try their website Kinetic Control, there maybe someone who can direct you.

If there are underlying structural (skeletal) asymmetries, which are extremely common, then obviously the overlying muscles will also appear asymmetrical. I remember as a student that every practical class we had we found that 90% of us were not symmetrical, had muscle weaknesses etc. etc.

Without a hands on assessment of the problem it is difficult to say whether it is the underlying skeletal structure or a muscular (training) related problem. I would tend to avoid chiropractors for this type of thing.

There may be little you can do to change this...it may just be how you were made and how you grew.